The drug substance used in the commercial drug product formulation of Pradaxa® is the methanesulfonate salt of dabigatran etexilate, which is chemically designated as β-Alanine, N-[[2-[[[4-[[[(hexyloxy)carbonyl]amino]iminomethyl]phenyl]amino]methyl]-1-methyl-1H-benzimidazol-5-yl]carbonyl]-N-2-pyridinyl-, ethyl ester, methanesulfonate salt of Formula I.

Dabigatran Etexilate of Formula II
is a prodrug of dabigatran of Formula III
which is a direct thrombin inhibitor. Dabigatran etexilate is indicated to reduce the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation. It may be used alone or in combination with other therapeutic agents.
U.S. Publication No. 2005/0234104 describes processes for the preparation of crystalline Forms I and II of the methanesulfonate salt of dabigatran etexilate. The crystalline Form I of the methanesulfonate salt of dabigatran etexilate is prepared by dissolving dabigatran etexilate in acetone followed by the addition of a solution of methane sulfonate in acetone.
PCT Publication No. WO 2012/077136 describes a process for the preparation of crystalline Form I of the methanesulfonate salt of dabigatran etexilate using an ester and alcohol solvent system, and specifically using ethyl acetate and ethanol solvents.
Processes for the preparation of dabigatran etexilate and its methanesulfonate salt are also described in U.S. Pat. No. 6,087,380 and PCT Publication Nos. WO 2012/027543, WO 2008/059029, WO 2011/110478, and WO 2006/131491.